旋转式能量回收装置水力冲击角度与转速特性研究
发布时间：2018-07-24 08:09
【摘要】：随着人们对节能的日益重视，，近些年反渗透海水淡化技术迅猛发展，能耗大幅降低。能耗的降低很大程度上有赖于能量回收装置的全面利用。能量回收装置可分为透平式和正位移式两种，作为正位移式能量回收装置的一种，水力自驱旋转式能量回收装置有结构紧凑、操控简便、流体连续性好等优点，成为近年来能量回收装置的研究热点。 本文设计并加工了6种螺旋导流块，其冲击角度分别为67.8°、68.5°、69.9°、72.5°、75.1°和77.9°。将上述螺旋导流块分别依次固定在不锈钢端盘上，然后将上下端盘以及转子组装成转芯，连同其它零部件一起装入有机玻璃筒体中组成水力自驱旋转式能量回收装置。在0.6MPa的系统压力下分别测定系统流量为5.1m3·h-1、5.8m3·h-1、6.5m3·h-1以及7.1m3·h-1时的转速，得出转速随系统流量、冲击角度的变化关系；设计并加工了一种带测速窗的不锈钢筒体，用其替换有机玻璃筒体，在高压下分别测定系统流量为8m3·h-1、9m3·h-1、10m3·h-1和10.7m3·h-1时的转速，得出转速随流量、压力、冲击角度的变化关系。上述实验结果表明：⑴随着系统流量的增大，转子转速呈增大的趋势；⑵随着冲击角度的变大，转速呈先增大后减小的变化趋势；⑶随着压力的上升，装置转速会先增大至最大值，然后逐渐减小直至进入一个不稳定区，最后降为零。装置在高压下不能稳定运行的原因为转子在转动过程中受到的阻力过大，阻力来源可能如下：⑴转芯同轴度的降低；⑵螺旋导流块上的沉头螺纹孔引起的涡流；⑶空蚀现象。本文对此进行了排除实验，结果表明阻力可能是由转芯同轴度降低以及空蚀现象引起。 本文对课题组已推导出的特定几何规格的水力自驱旋转式能量回收装置转速的理论计算公式进行了如下三项修正：⑴将转子所受动力矩计算过程进行修正；⑵将转子套筒与转子之间的周面粘性阻力矩的计算过程进行修正；⑶将上下端盘与转子上下端面之间的端面粘性阻力考虑进来。利用修正后的理论公式算出四个实验流量4.4m3·h-1、5.0m3·h-1、6.0m3·h-1和7.1m3·h-1下的理论转速值，将其与相应的实验转速值进行对比发现理论转速略高于实验转速，两者相对误差不超过12%，此误差来自于推导过程中的两项假设：⑴3#～5#流体通道所对应的冲击角度相同；⑵忽略了螺旋导流结构与转子之间的端面间隙泄露量。
[Abstract]:With the increasing attention to energy conservation, reverse osmosis seawater desalination technology has developed rapidly in recent years, and energy consumption has been greatly reduced. The reduction of energy consumption largely depends on the full utilization of energy recovery devices. The energy recovery device can be divided into turbine type and positive displacement type. As a positive displacement type energy recovery device, the hydraulic self-displacement rotary energy recovery device has the advantages of compact structure, simple operation, good fluid continuity, etc. In recent years, energy recovery devices have become a research hotspot. In this paper, six kinds of helical diversion blocks are designed and machined. The impact angles are 67.8 掳/ 68.5 掳/ 69.9 掳/ 72.5 掳/ 75.1 掳and 77.9 掳/ 77.9 掳respectively. The spiral flow guide block is sequentially fixed on the stainless steel end plate, and then the upper and lower end disks and the rotor are assembled into a rotary core, which, together with other parts, is mounted into the plexiglass cylinder to form a hydraulic self-displacement rotary energy recovery device. Under the system pressure of 0.6MPa, the rotational speed of the system flow rate was measured when the flow rate of the system was 5.8m3 h-1h-1 and that of 7.1m3 h-1 was 5.8m3 h-1h-1. The relationship between the rotational speed and the impact angle of the system flow rate was obtained, and a stainless steel cylinder with a speed measuring window was designed and manufactured, which was used to replace the plexiglass cylinder. The rotational speed of the system was measured at high pressure when the flow rate of the system was 8m3 h-1 / 9m3 / h ~ (-1) and 10.7m3 / h ~ (-1), respectively, and the relationship between the rotational speed and the flow rate, pressure and impact angle was obtained. The experimental results show that the rotor speed increases with the increase of the flow rate of the system, and the rotor speed increases with the increase of the impact angle, and the speed increases first and then decreases with the increase of the pressure. The rotational speed of the device increases to the maximum, then decreases gradually until it enters an unstable region and finally drops to zero. The reason why the device can not run stably at high pressure is that the rotor is subjected to too much resistance in the course of rotation. The source of the resistance may be as follows: 1 the coaxiality of the rotor core reduces the vortex cavitation caused by the screw hole of the countersunk head on the helical guide block. The results show that the resistance may be caused by the decrease of coaxiality and cavitation erosion. In this paper, the theoretical formula of rotational speed of hydrodynamic self-displacement rotary energy recovery device has been deduced by the following three amendments: 1: 1 to correct the calculation process of dynamic moment of rotor; The calculation process of the circumferential viscous resistance moment between the rotor sleeve and the rotor is modified. 3 the end surface viscous resistance between the upper and lower end disks and the rotor upper and lower face is taken into account. By using the modified theoretical formula, the theoretical rotational speed values of four experimental flows, 4.4m3 h-1n 5.0m3 h-1h ~ (-1) and 7.1m3 h ~ (-1), are calculated. It is found that the theoretical rotational speed is slightly higher than the experimental speed. The relative error is no more than 12. This error is derived from the two assumptions in the derivation process that the shock angle corresponding to the flow channel is the same and the leakage between the helical diversion structure and the end surface gap between the rotor is ignored.
【学位授予单位】：天津大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：P747
本文编号：2140759
[Abstract]:With the increasing attention to energy conservation, reverse osmosis seawater desalination technology has developed rapidly in recent years, and energy consumption has been greatly reduced. The reduction of energy consumption largely depends on the full utilization of energy recovery devices. The energy recovery device can be divided into turbine type and positive displacement type. As a positive displacement type energy recovery device, the hydraulic self-displacement rotary energy recovery device has the advantages of compact structure, simple operation, good fluid continuity, etc. In recent years, energy recovery devices have become a research hotspot. In this paper, six kinds of helical diversion blocks are designed and machined. The impact angles are 67.8 掳/ 68.5 掳/ 69.9 掳/ 72.5 掳/ 75.1 掳and 77.9 掳/ 77.9 掳respectively. The spiral flow guide block is sequentially fixed on the stainless steel end plate, and then the upper and lower end disks and the rotor are assembled into a rotary core, which, together with other parts, is mounted into the plexiglass cylinder to form a hydraulic self-displacement rotary energy recovery device. Under the system pressure of 0.6MPa, the rotational speed of the system flow rate was measured when the flow rate of the system was 5.8m3 h-1h-1 and that of 7.1m3 h-1 was 5.8m3 h-1h-1. The relationship between the rotational speed and the impact angle of the system flow rate was obtained, and a stainless steel cylinder with a speed measuring window was designed and manufactured, which was used to replace the plexiglass cylinder. The rotational speed of the system was measured at high pressure when the flow rate of the system was 8m3 h-1 / 9m3 / h ~ (-1) and 10.7m3 / h ~ (-1), respectively, and the relationship between the rotational speed and the flow rate, pressure and impact angle was obtained. The experimental results show that the rotor speed increases with the increase of the flow rate of the system, and the rotor speed increases with the increase of the impact angle, and the speed increases first and then decreases with the increase of the pressure. The rotational speed of the device increases to the maximum, then decreases gradually until it enters an unstable region and finally drops to zero. The reason why the device can not run stably at high pressure is that the rotor is subjected to too much resistance in the course of rotation. The source of the resistance may be as follows: 1 the coaxiality of the rotor core reduces the vortex cavitation caused by the screw hole of the countersunk head on the helical guide block. The results show that the resistance may be caused by the decrease of coaxiality and cavitation erosion. In this paper, the theoretical formula of rotational speed of hydrodynamic self-displacement rotary energy recovery device has been deduced by the following three amendments: 1: 1 to correct the calculation process of dynamic moment of rotor; The calculation process of the circumferential viscous resistance moment between the rotor sleeve and the rotor is modified. 3 the end surface viscous resistance between the upper and lower end disks and the rotor upper and lower face is taken into account. By using the modified theoretical formula, the theoretical rotational speed values of four experimental flows, 4.4m3 h-1n 5.0m3 h-1h ~ (-1) and 7.1m3 h ~ (-1), are calculated. It is found that the theoretical rotational speed is slightly higher than the experimental speed. The relative error is no more than 12. This error is derived from the two assumptions in the derivation process that the shock angle corresponding to the flow channel is the same and the leakage between the helical diversion structure and the end surface gap between the rotor is ignored.
【学位授予单位】：天津大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：P747
【参考文献】
相关期刊论文 前1条
1 石碧清;全玉莲;刘湘;;海水淡化膜法预处理技术研究现状[J];轻工科技;2012年05期
本文编号：2140759
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